Surgical stapling instrument

ABSTRACT

A surgical stapling instrument comprising a handle assembly having a proximal end, an elongated body portion extending distally from the handle assembly, a head portion disposed adjacent a distal portion of the elongated body portion and including an anvil assembly and a shell assembly. The shell assembly includes a shell and a staple guide housing a plurality of staples. A flexible engagement structure attaches the staple guide to the shell.

This application claims priority from provisional application Ser. No.61/255,544, filed Oct. 28, 2009, the entire contents of which areincorporated herein by reference.

BACKGROUND

1. Technical Field

The present disclosure relates generally to a surgical stapling devicefor applying surgical staples to body tissue. More particularly, thepresent disclosure relates to a surgical stapling device suitable forperforming circular anastomosis and/or treatment to internal walls ofhollow tissue organs.

2. Background of Related Art

Anastomosis is the surgical joining of separate hollow organ sections.Typically, an anastomosis procedure follows surgery in which a diseasedor defective section of hollow tissue is removed and the remaining endsections are to be joined. Depending on the desired anastomosisprocedure, the end sections may be joined by either circular, end-to-endor side-to-side organ reconstruction methods.

In a circular anastomosis procedure, the two ends of the organ sectionsare joined by means of a stapling instrument which drives a circulararray of staples through the end section of each organ section andsimultaneously cores any tissue interior of the driven circular array ofstaples to free the tubular passage. Examples of instruments forperforming circular anastomosis of hollow organs are described in U.S.Pat. Nos. 7,303,106 6,945,444, 6,053,390, 5,588,579, 5,119,983,5,005,749, 4,646,745, 4,576,167, and 4,473,077. Typically, theseinstruments include an elongated shaft having a handle portion at aproximal end to actuate the instrument and a staple holding componentdisposed at a distal end. An anvil assembly including an anvil rod withattached anvil head is mounted to the distal end of the instrumentadjacent the staple holding component. Opposed end portions of tissue ofthe hollow organ(s) to be stapled are clamped between the anvil head andthe staple holding component. The clamped tissue is stapled by drivingone or more staples from the staple holding component so that the endsof the staples pass through the tissue and are deformed by the anvil. Anannular knife is concurrently advanced to core tissue within the holloworgan to free a tubular passage within the organ.

Besides anastomosis of hollow organs, surgical stapling devices forperforming circular anastomosis have been used to treat internalhemorrhoids in the rectum. Typically, during use of a circular staplingdevice for hemorrhoid treatment, the anvil head and the staple holdingcomponent of the surgical stapling device are inserted through the anusand into the rectum with the anvil head and the staple holding componentin an open or unapproximated position. Thereafter, a pursestring sutureis used to pull the internal hemorrhoidal tissue towards the anvil rod.Next, the anvil head and the staple holding component are approximatedto clamp the hemorrhoid tissue between the anvil head and the stapleholding component. The stapling device is fired to remove thehemorrhoidal tissue and staple the cut tissue. In hemorrhoidectomy, thehemorrhoids are removed. Stapled hemorrhoidopexy is a surgical procedurein which the stapling device is used to remove tissue just above thehemorrhoids in order to pull the hemorrhoids back up inside the rectumand reduce the symptoms. The staples interrupt the blood flow of thesuperior hemorrhoidal arterial branches, cutting off the blood supply tothe tissue, thus causing the hemorrhoids to shrink.

Several known circular staplers have a shell assembly which contains astapler pusher and a staple guide which houses a plurality of staples ina plurality of annular rows. The staple guide in certain of theseinstruments is ultrasonically welded to the shell assembly. Althougheffective, alternative attachment methods could be advantageous from asecurement and a manufacturing standpoint.

SUMMARY

The present disclosure provides in one aspect a surgical staplinginstrument including a handle assembly, an elongated body portion, and ahead portion. The head portion is disposed adjacent a distal portion ofthe elongated body portion and includes an anvil assembly and a shellassembly. The shell assembly includes a shell and a staple guide housinga plurality of staples. A flexible engagement structure attaches thestaple guide to the shell.

In one embodiment, the flexible engagement structure includes at leastone hook on the staple guide. The shell can include a locking apertureconfigured and dimensioned to receive the hook of the staple guide.

In another embodiment, the flexible engagement structure includes aflexible tab on the shell. The flexible tab can include an aperture toreceive a hook on the staple guide. The hook can be substantially rigid.

In another embodiment, the shell assembly includes a plurality ofprojections extending distally to apply a distal force to the stapleguide. The projections can be compressible by the staple guide.

The present disclosure provides in another aspect a surgical staplinginstrument comprising a handle assembly including a movable handle foractuating the stapler, an elongated body portion extending distally fromthe handle assembly, and a head portion disposed adjacent a distalportion of the elongated body portion and including an anvil assemblyand a shell assembly. The shell assembly includes a shell and a stapleguide housing a plurality of staples. The staple guide includes a taband the shell assembly includes a slotted region having a first slottedportion and a second slotted portion angled with respect to the firstslotted portion. The tab is movable within the slotted region to attachthe staple guide and shell assembly.

In one embodiment, the first slotted region extends substantiallyaxially and the second slotted region extends substantially radially. Inone embodiment, the second slotted region has a reduced diameter sectionhaving a dimension smaller than an outer dimension of the tab.

DESCRIPTION OF THE DRAWINGS

Various embodiment of the presently disclosed surgical stapling deviceare disclosed herein with reference to the drawings, wherein:

FIG. 1 is a perspective view of an embodiment of the presently disclosedsurgical stapling instrument in an approximated position;

FIG. 2 is an exploded view of the shell assembly of the staplinginstrument of FIG. 1;

FIG. 3 is an enlarged view of the staple guide of FIG. 2;

FIG. 4 is an enlarged view of the area of detail designated in FIG. 3illustrating the flexible hook of the staple guide;

FIG. 5 is an enlarged view of the shell of FIGS. 1 and 2;

FIG. 6 is an enlarged view of the area of detail designated in FIG. 5showing the ramp and locking aperture;

FIG. 7 is a side perspective view of the shell assembly of FIG. 2;

FIG. 8 is a sectional view of the shell assembly of FIG. 7 taken alonglines 8-8 of FIG. 7;

FIG. 9 is a close up view in cross section of the area of detaildesignated in FIG. 8 showing engagement of the flexible hook of thestaple guide with the locking aperture of the shell;

FIG. 10 is a cross sectional view of the shell assembly prior toattachment of the staple guide showing flexure of the flexible hook;

FIG. 11 is a close up view in cross section of the area of detaildesignated in FIG. 10;

FIG. 12 is a close up view similar to FIG. 11 showing engagement of thestaple guide and shell in final assembly;

FIG. 13 is an exploded view of a shell assembly and staple guide of analternate embodiment of the present disclosure;

FIG. 14 is a close up view of the area of detail designated in FIG. 13showing the rigid hook of the staple guide;

FIG. 15 is a close up view of the area of detail designated in FIG. 13showing the engagement tab of the shell;

FIG. 16 is a close up cross-sectional view showing initial engagement ofthe staple guide and shell of FIG. 13 causing flexure of the hook;

FIG. 17 is a close up cross-sectional view similar to FIG. 16 showingengagement of the staple guide and shell in final assembly;

FIG. 18 is an exploded view of a shell and staple guide of anotheralternate embodiment of the present disclosure;

FIG. 19 is a close up view of the area of detail designated in FIG. 18showing the hook of the staple guide;

FIG. 20 is a close up cross-sectional view taken along 20-20 of FIG. 19showing the engagement of the staple guide and shell in the finalassembly;

FIG. 21 is an exploded view of a shell and staple guide of anotheralternate embodiment of the present disclosure;

FIG. 22 is a close up view of the area of detail designated in FIG. 21;

FIG. 23 is a close up view showing initial engagement of the locking tabof the staple guide of FIG. 21 in the slot of the shell;

FIG. 24 is a close up view of the locking tab of FIG. 23 moving radiallyin the slot of the shell;

FIG. 25 is a cross sectional view taken along line 25-25 of FIG. 24;

FIG. 26 is a close up view of the locking tab of FIG. 23 in the lockingposition within the slot of the shell; and

FIG. 27 is a cross sectional view taken along line 27-27 of FIG. 26.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the presently disclosed surgical stapling instrument willnow be described in detail with reference to the drawings in which likereference numerals designate identical or corresponding elements in eachof the several views.

Throughout this description, the term “proximal” will refer to theportion of the instrument closer to the operator and the term “distal”will refer to the portion of the instrument further from the operator.

With initial reference to FIG. 1, an embodiment of the presentlydisclosed surgical stapling device is shown generally as referencenumber 10. Briefly, surgical stapling device 10 includes a handleassembly 12, an elongated body portion 14 including a curved elongatedouter tube 15 extending from handle assembly 12, and a head portion 16extending from outer tube 15. Alternately, in some surgical procedures,e.g., the treatment of hemorrhoids, the body portion can besubstantially straight. The length, shape and/or the diameter of bodyportion 14 and head portion 16 may also be varied to suit a particularsurgical procedure.

In the illustrated embodiments, handle assembly 12 includes a stationaryhandle 18, a firing trigger 20, a rotatable approximation knob 22 and anindicator 24. Head portion 16 includes an anvil assembly 30 and a shellassembly 31. Anvil assembly 30 is movable in relation to shell assembly31 between spaced (unapproximated) and approximated positions. Anvilassembly includes an anvil shaft mounted (preferably removably mounted)to an anvil retainer of the surgical stapling instrument 10.

In operation, rotation of approximation knob 22 causes movement of anvilassembly 30 in relation to shell assembly 31 between spaced andapproximated positions, as approximation knob 22 is mechanically engagedwith an anvil retainer via bands which is connected to anvil assembly30. It is envisioned that rotation of approximation knob 22 in a firstdirection (e.g., clockwise) causes proximal movement of anvil assembly30 to an approximated position to clamp tissue between the anvil andshell assemblies and rotation of approximation knob 22 in a secondopposite direction (e.g., counter-clockwise) causes distal movement ofanvil assembly 30 to an unapproximated position.

Actuation of firing trigger 20 (i.e., pivoting in the direction towardthe stationary handle 18), causes staples to be ejected from shellassembly 31 towards anvil assembly 30. That is, firing trigger 20 isdisposed in mechanical cooperation with a staple pusher or pusher back50 (FIG. 2) such that actuation of firing trigger 20 causes advancementof pusher 50 through the staple guide 60 and into contact with thestaples 70 housed in an annular array(s) in staple guide 60. This forcesthe staples 70 out of staple pockets or slots 33 into staple deformingpockets of anvil assembly 30. Pusher 50 includes a plurality of distallyextending pusher fingers 52 which contact the staples 70 to advance theminto contact with the anvil. A circular knife 74 is frictionallyretained with the central throughbore 51 of pusher back 50 to fixedlysecure knife 74 in relation to pusher back 50. Knife 74 is advanceablewith the pusher back 50 to sever tissue between the annular rows ofstaples 70. Throughbore 51 is slidably positioned about inner guideportion 35 of shell 31. Distal cylindrical section 53 of pusher 50 isslidably positioned within distal cylindrical section 34 of shell 31.The proximal end of pusher back 50 includes members 55 which areconfigured to lockingly engage with a pusher link (not shown). Shell 31can also include vent holes 32.

Further details of the features of surgical stapling device 10, such asthe approximation assembly and firing assembly, are disclosed incommonly-owned U.S. Pat. Nos. 7,303,106, 7,234,624 and 7,168,604, theentire contents of which are incorporated by reference herein.

FIGS. 2-12 illustrate a first embodiment of the flexible engagementstructure for attaching the staple guide 60 to the shell assembly 31.With initial reference to FIGS. 3 and 4, a flexible hook 80 on an outersurface of staple guide 60 extends in a proximal direction, preferablyterminating at the proximal end of staple guide 60. The hook 80 isproximal of flange 61 of staple guide 60. The hook can be substantiallyflush with the outer surface 63 of staple guide 60. Hook 80 has anangled proximal surface 82, angled with respect to a longitudinal oraxial region 89 extending from the staple guide 60. The hook 80 ispreferably formed integrally with the staple guide 60, however,alternatively, it could be a separate element(s) attached to the stapleguide 60. Two or more hooks are preferably provided to engage at spacedregions along the shell 31. For example two hooks can be placedapproximately 180 degrees apart, three hooks at approximately 120degrees apart, etc. The illustrated embodiment shows four hooks 80spaced approximately 90 degrees apart. Other spacings, includingnon-equidistant spacings of the hooks, are also contemplated.

Referring to FIGS. 5, 6 and 9, shell assembly 31 includes lockingapertures 36, preferably spaced slightly proximally from the distal edge31 a of shell 31, each configured and dimensioned to receive a hook 80.Angled wall or ramp 37 on the inner wall of the shell 31 facilitateshook engagement as described below.

As can be appreciated by viewing FIGS. 10-12, during assembly whenstaple guide 60 is attached to the shell assembly 31 by placement in adirection of arrow A, each hook 80 initially flexes radially inwardly(downwardly in the orientation of FIG. 10) in the direction of arrow Bas the surface of angled wall 37 of shell 31 is engaged by angledsurface 82 of the hook 80 of staple guide 60. Upon sufficient distaladvancement in manufacture in the direction of arrow A, the proximal endof hook 80 passes beyond angled surface 37 and beyond wall 38 and thenbeing no longer biased radially inwardly (downwardly in the view of FIG.11), can move radially outwardly (upwardly) in the direction of arrow Cto its normal unstressed condition to extend within locking aperture 36.As shown, in this position, the engagement of shoulder 84 of hook 80with wall surface 37 a prevents distal movement of the staple guide 60to retain it in position secured to the shell 31 (see also FIG. 9).During use, a distal force applied to the staple guide duringmanipulation of the instrument or firing of the staples will notdislodge the staple guide 60 from the shell assembly 31 since distalmovement is prohibited by wall 37 a. Each of the hooks 80 engages acorresponding locking aperture 36 in the same manner as described above.Note that preferably the hook 80 does not extend beyond the outerconfines (outer diameter) of the aperture 36 so as to not extend pastthe outer surface 39 of shell 31.

In the alternate embodiment illustrated in FIGS. 13-17, a rigid hook isutilized. Shell 110 is identical to shell 31 of FIG. 2 except for thestructure cooperating with the hooks of the staple guide. Morespecifically, shell 110 has a flexible tab 120 formed by cutouts 122,124 in the distal end 112 of the shell 110. The flexible tab 120 has alocking aperture 126 formed therein. Staple guide 140 is identical tostaple guide 60 of FIG. 2 except for the hook configuration. Morespecifically, staple guide 140 has a hook 142 formed thereon, which ispreferably substantially rigid. As shown, the hook 142 extendsproximally from staple guide 140 and at its proximal end has an angledproximal surface 144 and vertical surface 147 substantiallyperpendicular to a longitudinal axis of staple guide 140. A longitudinalor axial region 145 extends distally. A plurality of tabs 120 areprovided in shell 110, each dimensioned and configured to receive a hook142.

As can be appreciated by viewing FIGS. 16 and 17, when staple guide 140is attached during assembly to the shell assembly 110 by placement in adirection of arrow D, the tab 120 of the shell 110 initially flexesradially away (upwardly in the orientation of FIG. 16) away from theshell 110 in the direction of arrow E as angled surface 144 of hook 142engages the edge 121 of distal tab portion 123 of the tab 120. The edge121 can optionally be angled to engage the angled surface 142 of hook140. Upon sufficient distal advancement in manufacture in the directionof arrow D, the angled wall 144 of hook 140 passes beyond edge 121 andbeyond distal tab portion 123, and then the distal tab portion 123, nolonger biased upwardly (radially), can move downwardly (inwardly towardthe longitudinal axis) in the direction of arrow G toward the shell 110so the hook 142 is seated within locking aperture 126. As shown, in thisposition, the engagement of shoulder 145 a of hook 142 with wall 127 ofdistal tab portion 123 prevents distal movement of the staple guide 140to retain it in position. During use, a distal force applied to thestaple guide 140 during manipulation of the instrument or firing of thestaples will not dislodge the staple guide 140 from the shell assembly110 since distal movement is prohibited by wall 127.

In the alternate embodiment of FIGS. 18-20, flexible engagement bumpsare provided. Staple guide 170 is identical to staple guide 60 of FIG. 2and shell 180 is identical to shell 31 of FIG. 2 except for thestructure cooperating with the hooks of the staple guide and theflexible bumps. More specifically, staple guide 170 has a flexible hook172 extending proximally. Shell 180 has a locking aperture 182dimensioned and configured to receive the hook 172. Hook 172 flexes asit is inserted past wall 183 positioned distal of locking aperture 182.The distal end of the wall 183 preferably has an angled surface 185cooperating with the angled surface 174 of hook 172 to facilitateinsertion. During assembly, wall 183 biases hook 172 radially inwardlyin a similar fashion as hook 84 of FIG. 2 to enable it to passproximally beyond wall 183, and then the hook 172 returns to its normalposition received in locking aperture 182 as shown in FIG. 20. Duringuse, a distal force applied to staple guide 170 will not dislodge thestaple guide 170 from shell assembly 180 since distal movement isprohibited by engagement of shoulder 175 with wall 189.

Shell 180 can also have a series of flexible bumps or projections 186 toenhance securement of the staple guide 170. Bumps 186 extend distallyfrom distal edge 187 of shell 180. When the staple guide 170 is attachedto the shell 180, the flexible bumps or projections 186 are pressedinwardly. As a result, after assembly, the bumps 186 provide a distalforce on the staple guide 170, thereby forcing hook 172 (shoulder 175)distally against surface 189 of wall 183 to the extent there is anyslack between the shoulder 175 of hook 172 and the wall 189 adjacentlocking aperture 182 when assembled. Consequently, the bumps/projections186 function similar to a spring biasing the staple guide 170 in adistal direction when assembled to the shell 180. It should beappreciated that the bumps or projections can be provided on the otherembodiments of the shell disclosed herein to provide a distal biasingforce if desirable.

FIGS. 21-27 illustrate another alternate embodiment for attaching thestaple guide to the shell assembly utilizing a bayonet mount. Shell 210is identical to shell 31 of FIG. 2 except for the structure cooperatingwith the tabs of the staple guide. More specifically, shell 210 has aslotted region 212. Slotted region 212 extends proximally from a distaledge 214 of the shell 210 in a longitudinal (axial) direction forming anaxial slotted region 212 a of slot 212. Slot 212 also has a radiallyextending region 212 b transverse to the axial region 212 a, therebyforming a substantially L-shape slotted configuration. A blockingindentation 213 extends into radial region 212 b. For ease ofexplanation blocking recess or indentation 213 can be considered asdividing radial region 212 b into two sections.

Staple guide 230 is identical to staple guide 60 of FIG. 2 except forthe structure engaging the shell 210 for attachment thereto. Morespecifically, staple guide 230 has a locking tab 232 at a proximal edge234. As can be appreciated by viewing FIGS. 23-27, when staple guide 230is attached during assembly to the shell assembly 110 by placement in adirection of arrow E, the locking tab 232 enters the axial region 212 aof slot 212. After the locking tab 232 is inserted to the edge 212 c ofaxial region 212 a (see FIG. 23), staple guide 230 is then rotated andthe tab 232 is moved in the radial region 212 b of slot 212 in thedirection of arrow F of FIG. 24. Rotation continues until tab 232 isforced past blocking recess 213 as shown in FIG. 26. That is, as tab 232moves along the radial region 212 b of slot 212, it is forced pastlocking recess 213 which forms a reduced diameter region 212 f of region212 b of slot 212 (The region 212 f has a smaller dimension than atransverse dimension of the locking tab 232). Once moved past thisreduced diameter region 212 f, the region prevents withdrawal of thelocking tab 232, i.e. movement in the direction opposite the directionof arrow F, unless a sufficient force is applied by rotation of theshell guide 230 to overcome the blocking recess (indentation) 213 andpass by the reduced diameter region. Note that the structure can beprovided so that either the tab 232 flexes or the indented wall formingthe blocking recess 213 flexes so the tab can move past the indentation.During use, a distal force applied to the staple guide 230 duringmanipulation of the instrument or firing of the staples will notdislodge the staple guide 230 from the shell assembly 210 since distalmovement is prohibited by wall 233 and disconnection requires reverserotation of the staple guide 230 to remove it from the slot 212.

It will be understood that various modifications may be made to theembodiments disclosed herein. Therefore, the above description shouldnot be construed as limiting, but merely as exemplifications ofdisclosed embodiments. Those skilled in the art will envision othermodifications within the scope and spirit of the claims appended hereto.

1. A surgical stapling instrument, comprising: a handle assemblyincluding a movable handle for actuating the stapler; an elongated bodyportion extending distally from the handle assembly; a head portiondisposed adjacent a distal portion of the elongated body portion andincluding an anvil assembly and a shell assembly, the shell assemblyincluding a shell and a staple guide housing a plurality of staples; anda flexible engagement structure attaching the staple guide to the shell.2. The instrument of claim 1, wherein the flexible engagement structureincludes at least one hook on the staple guide.
 3. The instrument ofclaim 2, wherein the shell includes a locking aperture configured anddimensioned to receive the hook of the staple guide.
 4. The instrumentof claim 1, wherein the flexible engagement structure includes aflexible tab on the shell.
 5. The instrument of claim 4, wherein theflexible tab includes an aperture to receive a hook on the staple guide.6. The instrument of claim 5, wherein the hook is substantially rigid.7. The instrument of claim 5, wherein the flexible tab is positioned atthe distalmost end of the shell.
 8. The instrument of claim 1, furthercomprising at least one flexible projecting member compressible by thestaple guide.
 9. The instrument of claim 3, wherein the hook includes anangled surface engageable with a wall adjacent the locking apertureduring assembly to cause flexing of the hook.
 10. The instrument ofclaim 1, wherein the shell assembly includes a plurality of projectionsextending distally to apply a distal force to the staple guide.
 11. Theinstrument of claim 10, wherein the projections are compressible by thestaple guide.
 12. The instrument of claim 10, wherein the projectionsextend from a distalmost end of the shell.
 13. A surgical staplinginstrument, comprising: a handle assembly including a movable handle foractuating the stapler; an elongated body portion extending distally fromthe handle assembly; and a head portion disposed adjacent a distalportion of the elongated body portion and including an anvil assemblyand a shell assembly, the shell assembly including a shell and a stapleguide housing a plurality of staples, the staple guide including a taband the shell assembly including a slotted region having a first slottedportion and a second slotted portion angled with respect to the firstslotted portion, the tab movable within the slotted region to attach thestaple guide and shell assembly.
 14. The instrument of claim 13, whereinthe first slotted region extends substantially axially and the secondslotted region extends substantially radially.
 15. The instrument ofclaim 14, wherein the second slotted region has a reduced diametersection having a dimension smaller than an outer dimension of the tab.